A lawyer is cross-examining a doctor on the stand about whether or not he had checked the pulse of the deceased before he signed the death certificate.
"No," the doctor said, "I did not check his pulse."
"And did you listen for a heartbeat?" said the lawyer.
"No, I did not," said the doctor.
"So," said the lawyer, "when you signed the death certificate, you had not taken steps to make sure he was dead."
The doctor, having enough of the lawyer's redicule, stated, "Well, let me put it this way. The man's brain was in a jar on my desk, but for all I know he could be out practicing law somewhere."